I may be seriously late to the party on this one, but I realized something about Scott Pilgrim VS The World, and that is that video games play no part in the story at all. All of the retro video games stuff is only occurring in Scott's mind when he is around or thinking about Ramona. At the start of the movie ( I'll be referencing the movie for this since I unfortunately never read the graphic novel. ) but at the start of the movie, when Scott is hanging out with Knives and the band, nothing video game-y happens at all. Every fight scene and video game reference occurs when Scott is fighting an Evil Ex for Ramona or just being with her. In fact, I don't even think an actual fight ever happened for real. It was all just how Scott's mind processed the emotional struggles of dealing with Ramona's past and getting through all the generic relationship issues that everyone has to go through.